VBA code for change vlookup formula to vlookup formula with ISNA

DEAR ALL

I required a vba code to convert the vlookup formula to vlookup with ISNA formula

For example I put a vlookup formula in cell H3 as “+ VLOOKUP(G3,$B$3:$C$5,2,0)”
To include ISNA formula I need to do following actions
1. I press F2 in cell H3.
2. Copy the formula without + or = Symbol like “VLOOKUP(G3,$B$3:$C$5,2,0”
3. Clear the contents in Cell H3.
4. Type the formula like “+If(isna(Paste formula),0,Paste formula)
I tried through macro recording but its not help ful.

Any one help me in this regard.
Regards.

Prasanna.E